Slide for protection of an opening in the base plate of a sewing machine

ABSTRACT

Sewing machines of the type having an opening or aperture in the base plate adjacent the stitch plate to provide access to the looper or other stitch forming means below the base plate, are provided (1) with a slider or closure for such aperture, the slider being curvable or bendable about an axis running transversely to the direction of movement of the slider, and (2) with a passageway which guides the end of the slider downwardly within the edges of the base plate when moved to open the aperture.

United States Patent Schneider et al.

[ Mar. 26, 1974 SLIDE FOR PROTECTION OF AN OPENING IN THE BASE PLATE OFA SEWING MACHINE [75] Inventors: Franz Schneider; Herbert Wenz,

both of Kaiserslautern, Germany [73] Assignee: Pfaff IndustriemaschinenGmbI-I,

Kaiserlaufen/Pfalz, Germany [22] Filed: Oct. 3, 1972 [21} Appl. No.:294,576

[30] Foreign Application Priority Data Oct. 12, 1971 Germany P 21 50774.4

[52] U.S. Cl. 112/260 [51] Int. Cl DOSb 73/12 [58] Field of Search112/260, 258

[56] References Cited UNITED STATES PATENTS 2,75l,869 6/1956 Walcoff112/260 I 2 25 I4 13 0 l A 77 3,545,393 12/1970 Meier ..ll2/260 PrimaryExaminer-George H. Krizmanich Attorney, Agent, or Firm-Greene & Durr [57] ABSTRACT Sewing machines of the type having an opening or aperture inthe base plate adjacent the stitch plate to provide access to the looperor other stitch forming means below the base plate, are provided (1)with a slider or closure for such aperture, the slider being curvable orbendable about an axis running transversely to the direction of movementof the slider, and (2) with a passageway which guides the end of theslider downwardly within the edges of the base plate when moved to openthe aperture.

2 Claims, 4 Drawing Figures SLIDE FOR PROTECTION OF AN OPENING IN THEBASE PLATE OF A SEWING MACHINE The invention concerns a sewing machinewith a slide which protects or walls off an opening in the base plate ofthe sewing machine which is provided to cover the area over the stitchforming device.

Generally, these apertures in the base plate are covered by a rigidslide which is accommodated in guide grooves of the base plate. Byaligining the upper surface of such a slider with the goods contactingsurface or upper surface of the base plate, while a thin edge of theslider is surrounded by the base plate edges. For opening or exposingthe aperture, the slider will be pushed from its covering position sothat a part of the slider projects away from the edge of the base plate.A slider of this kind is especially disadvantageous when the sewinggoods support surface of the base plate has been aligned with the tabletop of a supporting table. In this case, the slider can be pushed toopen position only when the sewing machine is lifted or pivoted upwardlybeforehand. Besides, there exists the danger that, through carelessness,the sewing machine will drop, while the slider is still in openposition, and thereby injure the table top and bend the slider.

A further important drawback of the conventional slider relates to thefact that different sized openings in the base plate necessitate manydifferent sizes of sliders. There is such a necessity, for example, withtwoneedle sewing machines where the breadth of the stitch plate fordifferent needle spacing and therefore the size of the opening to becovered in the base plate changes.

This invention is based on the problem of providing a protecting ocverfor the opening in the base plate of sewing machine which in the closedand in the open positions remains within the edges of the base platesurrounded in the vertical reaches of the base plate and which is soconstructed that one size of slider or protecting cover serves to coverthe openings when various sizes of stitch plates are employed.

The solution of this problem comprises the employment of a slidercovering means which is deformable laterally to the shifting directionabout a bending axis and which is downwardly divertable through a guidemeans in the area of the base plate edge.

Through the structure of the invention, a slider is provided, which ismoved out into its open position by sliding the same back and downwards,within the reaches of the base plate and not just laterally on the baseplate. On this basis, such a slider can also be moved to open positionwhile the sewing machine is supported at table top level on a supportingstructure.

With different size openings in the base plate, the slider of theinvention will be shifted more or less further in the direction of thestitch plate for the'protection of the opening, whereby the part of theslider not required for the covering of the actual opening is placed inits downwardly curved position. Similar and like-sized sliders of theinvention can be employed for one-needle sewing machines and fortwo-needle sewing machines with different sized needle spacing. Thisresults in a reduction in the cost of manufacture and simplifies storageof the sliders.

Where, generally, only a slight spacing is available between the looperdevice of a sewing machine and the covering slider, care must be takenas to such details, that the slider of the invention must not be allowedto be pressed down onto the looper. Accordingly, the invention furtherproposes to couple the slider at the end adjacent the stitch plate witha bend resistant plate. This plate, by way of example, can be made ofthe known rigid steel plate covering material, and covers the looper atthe front part of the slide to thereby prevent sagging of this part ofthe cover upon the occurrence of a relatively large downwardly directedforce which sagging would prevent the rotary motion of the looper andthe stitch forming operation.

Further details of the invention are given in the following descriptionof specific examples shown in the drawing. In the drawing:

FIG. 1 is a plan view of a base plate of a sewing machine equipped witha slider made according to the invention.

FIG. 2 is a transverse section of the slider of the invention taken onlines II II of FIG. 1.

FIG. 3 is a transverse sectional view, with one part cut away, taken online III III of FIG. 1 showing the slider of the invention.

FIG. 4 is a greatly enlarged detail view of an end portion of a slidermade according to the invention.

In the table plate 1 of the sewing machine chassis, the base plate 2 ofa two-needle machine is fixed, wherein for the sake of clarity, thesupports and casing bracket are not shown. The sewing goods contactsurface 3 of base plate 2 lies in the plane of the upper side of thetable plate 1. In the base plate 2, there is positioned a stitch plate 4for a porportionally predetermined broad needle spacing by which thestitch holes 5 are separated correspondingly from one another. Accordingto FIG. 1, there is arranged to the right of the stitch plate 4, a rigidslider 6 which covers the right looper (not shown) of the sewingmachine. The slider 6, with its upper side within the plane of thecontact surface 3 of base plate 2 for the sewing goods, can be pushedhorizontally to an open position, there being provided in the base plate2 a recessed surface 7 adapted to receive the lower surface of slider 6.

The slider 8 of the invention serves as a cover for the left looper 9,which are sketched in FIG. 2 in dot-dash lines, or for the closure ofthe opening 11 of the base plate 2 extending between the left edge ofstitch plate 4 (FIGS. 1 and 2) and the shouldered thicknening 10 (FIG.2) of the base plate 2.

The slider 8 comprises a unit-to-unit resilient, tearresistant,synthetic material, polyamide for example, manufactured plate, which onits underside has a plurality of grooves 12 extending laterally of theslide direction, V. At the ends of the ribs 13 which extend betweenlateral grooves 12, laterally extending short guiding cars 14 areformed.

The slider 8 is made by injection molding techniques, suitablearrangements can be made to have the slider 8 united with the plate 15simultaneously with the molding of the slider 8.

By way of a specific example, the plate 15 is formed with a cleft 17therein and the cleft is provided with a plurality of holes 18 (see FIG.4). Such a plate 15 is inserted in the mold in such a way that duringmolding, the holes and the cleft are filled in so that the slider 8 isfirmly bonded to the plate 15.

In the base plate 2, a surface depression 19 is provided passing alongthe sides of the opening 1 1, extend- 3 ing parallel to the sewing goodssupporting surface to about the middle of the shoulder and proceedingfrom there to curve downwardly.

Inserted in the depression 19 is a U-form frame having two legs 21extending horizontally along the area of the shoulder 10, the legs beingconnected by a guide strip 22, and with the upper side of said framelying in the plane of the sewing goods surface 3. The guide strip 22reaches up to the edge 23 of the base plate 2 and has an undersideadapted to follow the curved part of depression 19.

On the underside of the legs 21 facing, along-side the longitudinaldirection of the opening 11, there is provided a longitudinal recess 24(FIG. 3) which continues on the underside of curved guide strip 22 toprovide continuous recesses 24.

In the guide strip 22, a further recess 25 is provided which liessymmetrical with recess 24, is likewise curved and is about twice asdeep as recess 24. The depression l9 and the frame 20, accordingly formtwo straight guide grooves 26, in the area oflegs 21 and also form, inthe area of guide strip 22, a curved, shaded-off guide groove 27 inwhich are arranged, respectively, the guide lugs 14 of slider 8 and theguide lugs 16 of plate 15.

By shifting in the slide direction V, the entering part of slider 8 willbe steered either into the curved guide groove 27 or the horizontalposition, the lateral grooves 12 thereof facilitating the deflecting orcurving operation.

The downwardly deflected part of slider 8 remains enclosed within theedge 23 of the base plate along a vertical plane in the vertical regionof the base plate wherefore the slider 8 also can be pushed to the openposition when a sewing machine is mounted on a support with its sewingsurface aligned in the plane of the upper surface of the support.

When using a narrow stitch plate, the slider can be pushed still furtherto the right, as shown in the drawing, without having its end slid outof the guideway 27. For this object, the legs 21 of frame 20 areconstructed so that they reach to the left edge of the narrowest stitchplate.

The width of plate 15 corresponds essentially to the diameter of theloopers 9 so that it is guaranteed that the part above the looper of thecover of the invention has great strength so as not to sag down tocontact the looper.

Where the slider 8 consists of resilient material, and accordingly toprevent buckling is given certain strength, the effort is made toclosely fit the slider within the arched recesses 24,25. Fundamentally,the depression 19 in the region of the connecting part 22 is notrequired to be curved as shown. It suffices when the shouldered portionis beveled at the edge with the corners rounded off.

I claim:

1. In a sewing machine of the type having a base plate, a stitch platein the base plate, and an aperture in said back base plate adjacent thestitch plate and above a stitch forming device, the improvementcomprising a slider comprising a resilient portion for covering saidaperture, guide means in the base plate for guiding said slider back andforth in one direction, said guide means comprising a downwardlydiverted portion in that area of said aperture nearest the edge of thebase plate, the resilient portion of said slider comprising a platewhich is provided on its under side with a series of grooves directedtransversely with respect to the direction of movement of the sliderwhereby said slider is adapted to follow the diverted portion of saidguide means.

2. A sewing machine as claimed in claim 1 wherein said slider has anattached bend resistant portion at the end nearest the stitch plate ofthe machine.

1. In a sewing machine of the type having a base plate, a stitch platein the base plate, and an aperture in said back base plate adjacent thestitch plate and above a stitch forming device, the improvementcomprising a slider comprising a resilient portion for covering saidaperture, guide means in the base plate for guiding said slider back andforth in one direction, said guide means comprising a downwardlydiverted portion in that area of said aperture nearest the edge of thebase plate, the resilient portion of said slider comprising a platewhich is provided on its under side with a series of grooves directedtransversely with respect to the direction of movement of the sliderwhereby said slider is adapted to follow the diverted portion of saidguide means.
 2. A sewing machine as claimed in claim 1 wherein saidslider has an attached bend resistant portion at the end nearest thestitch plate of the machine.